From Press Release:
December 5, 2018 – Cary, North Carolina — Today, Epic Games has announced a brand new way to experience the world of Fortnite — Fortnite Creative! Available on December 6 with the launch of Season 7, Fortnite Creative lets players design games, battle friends in new ways, and build the Fortnite of their dreams. It all happens on their own private island where everything they make is saved.
Season 7 Battle Pass owners will have access to their own private island for the first week of Season 7. During this early access week Battle Pass owners can invite their friends to play on their island. Starting December 13, all players will have access to a private island for free. Check out this video for more.
For more information on Fortnite Creative, head over to the official Fortnite blog for more details.